# Backpropagation
**Domain:** Machine Learning / Optimization / Neural Networks
**Doc Type:** Technical Concept Node
**Maturity:** Developed
**Related:** [[wiki/Artificial Neural Networks|Artificial Neural Networks]], [[wiki/Geoffrey Hinton|Geoffrey Hinton]], [[wiki/Yann LeCun|Yann LeCun]]
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## Definition
**Backpropagation** is the efficient application of the chain rule for calculating how a network's error changes with respect to its parameters. Those gradients allow an optimization procedure to adjust weights throughout a multilayer computational graph.
## Ontology Context
Backpropagation is a training calculation, not an intelligence theory and not a complete learning system. It routes to [[wiki/Artificial Neural Networks|Artificial Neural Networks]] for the trained architecture and to the relevant person nodes for historical research lineages.
## See Also
[[wiki/Artificial Neural Networks|Artificial Neural Networks]] · [[wiki/Geoffrey Hinton|Geoffrey Hinton]] · [[wiki/Yann LeCun|Yann LeCun]] · [[wiki/Deep Learning|Deep Learning]]